Confused with this probability question

[super112]

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What's the probability of rolling a die twice and getting at least one number greater than 1.

I was thinking odds of getting 2,3,4,5, or 6 on one roll and on the second would mean 5/6 * 5/6 but answers show the method using 1-P(getting 1 on both rolls) which equals 35/36.

I suppose I can just learn to do it their way, but I don't understand why my method gives a different value.

Thanks.

 

[baronen26]

in this case, order doesn't matter. you only need to get 23456 on one roll. you are doing the problem as if you need to get 23456 on both rolls

 

[PointEstimate]

What's the probability of rolling a die twice and getting at least one number greater than 1?

You can have roll a 1 on the first roll and so long as the second roll is not a 1, then you have satisfied the question. Put another way, if you roll a die twice, you have to get a least 1 of those rolls to be 2 or greater.
That's why you want to calculate the probability of getting 1 on both rolls (1/6)*(1/6) and subtract that from 100%, leaving 35/36.

The way you calculated it, you determined the probability of rolling 2 or greater for both rolls or the probability of not rolling a 1 in 2 independent rolls of the die.

 

[super112]

thanks guys, I appreciate the explanations!